Notice whether you get symptoms after eating foods with wheat, barley, or rye
Watch for bloating, gas, abdominal pain, diarrhea, constipation, nausea, or vomiting
Pay attention to non-digestive symptoms such as fatigue, headache, brain fog, joint pain, or skin issues
Track whether symptoms improve when you avoid gluten and return when you eat it again
Keep a food and symptom diary for at least a couple of weeks
Check whether symptoms happen consistently after gluten-containing meals
Rule out celiac disease first with a doctor before removing gluten long term
Rule out wheat allergy if you have hives, swelling, wheezing, or trouble breathing
Consider non-celiac gluten sensitivity if celiac disease and wheat allergy tests are negative
Ask a doctor about testing before starting a gluten-free diet
Seek medical advice if symptoms are severe, persistent, or causing weight loss, blood in stool, or anemia